Innovative Long-Shelf-Life Prepreg Systems
Solvent-free prepreg technologies with significantly extended storage shelf lives Winner at JEC Asia Innovation Awards – Category: Prepregs Gurit has developed a range of solvent-free prepreg technologies with significantly extended storage shelf lives. Pre-impregnated composite fibers containing a pre-catalysed epoxy resin system require cold storage to prevent a staging reaction from occurring before use. This staging reaction is accelerated with elevated temperatures, which can be problematic in countries with warmer climates.
Life span of 2 months at elevated temperature of 35°, and 6 months at 21°C
Gurit’s long-shelf-life prepreg chemistry allows prepregs to be produced with a life span of up to 2 months whe stored at an elevated temperature of 35°C, and greater than 6 months at 21°C, depending on the system. Gurit achieved this by using advanced catalyst chemistry to provide increased stability at storage temperatures, yet remain reactive at temperatures of 85°C and above, allowing fast curing of components. This allows users to replace their current prepregs with a long-shelf-life version generating savings in their storage requirements, simplifying their inventory management and without changing their curing cycle or finished material properties.
Focus on improving latency of the catalysts used to cure epoxy prepregs
The Product Development department initially focused on improving the latency of the catalysts used to cure epoxy prepregs. The challenge was to significantly increase the latency at ambient temperatures without reducing the reactivity at the higher temperature used for curing. Once the core chemistry was developed, Gurit proceeded to formulate this into a range of prepregs for different applications. Initially, three different prepregs were developed: one for industrial applications (wind turbine blades), one for low-temperature component manufacture (marine race yachts), and one for high-performance autoclave parts (marine masts and spars). During this development, the project team optimised the formulations to ensure that mechanical and thermal properties were maintained. The teams then ensured that these new systems could be manufactured on a production scale. Once this work was completed, production samples were manufactured for beta testing with selected customers.